本文研究了PMU的配置方法,然后将PMU应用于电网稳定分析当中,提出实现“在线预决策,实时匹配”控制策略的分析和控制流程框图,并对云电送粤输电断面对系统稳定的影响进行了分析,具体内容如下:
1、介绍EEAC法的原理,分析了EEAC法和定量分析在电力系统在线稳定分析中的优势,给出与定量分析相关的概念。
2、就经济、技术等方面的原因,分析目前PMU配置方法的不足,指出电网的完全可观测是电网发展中的理想状态,具有理论上的意义。但是,就电网目前的情况分析,还难以实现。因此需要从工程化角度,考虑电网的运行及性价比,提出合理有效的实用化PMU配置方法;
3、根据PMU的作用总结了在WAMS中配置PMU的原则,提出了主网架的构建和关键节点选取的原则,并且给出间接可观的原则。然后以工程实用为基础,以主网架及关键节点可观为目的,结合间接可观的概念,利用最小生成树(MST)搜索算法和模拟退火(SA)校核算法,提出主网架可观的PMU最优配置方法。为了将SCADA/EMS信息与PMU的信息形成互补,提出了二者之间数据处理的三种方法:信息辐射法、曲线拟合法以及等值导纳法。经IEEE14节点、新英格兰39节点、FASTEST22节点系统验证了配置方法的可行性,并根据云南电网现状,提供了建议性的PMU配置方案。
4、结合中国老一辈电力工作者提出的电力系统“三道防线”的概念,针对“在线预决策,实时匹配”的控制策略表生成方案,给出基于PMU的互联电网稳定控制流程框图,将PMU和EEAC法结合起来应用于互联电网的稳定预测及控制,提出预防控制、紧急控制和校正控制一体化构想,令其形成闭环滚动式的控制结构,并在FASTEST22节点系统中对三种控制的预测进行验证,结果表明本方案在理论上是可实现的,具有一定的发展前景;
5、根据输电断面、关键输电断面等相关概念以及输电断面的意义,分析了云南电网输电断面的特点,然后基于电力系统暂态定量分析软件(FASTEST)和电力系统综合分析程序(BPA),结合云南电网的实际运行情况,对2006年和2007年丰大运行方式下,云电送粤输电断面对系统稳定的影响进行了初步研究,最后针对2010年云南电网将建成kV东送交直流混合输电线路,形成省内交直流混合外送输电断面这一情况,结合输电断面潮流静态安全约束的数学模型以及PMU量测,提出一种基于直流潮流的大型互联电网分析方法。
关键词:PMU布点;最小生成树算法;模拟退火算法;控制策略;外送断面;
ABSTRACT
The PMU placement which is based on MST-SA and the power system on-line stability analysis which is based on PMU and the effect of transmission section of Yunnan power system are analyzed and studied in this paper:
1. The principle of EEAC method and the advantage of EEAC and quantitative analysis are analyzed and introduced;
2. Analyzing shortage of others PMU placement methods with the reason of economy and technology. The completely observation is ideality state for the developing of power system, and which is significative in theory but not practicality. Every method is difficult to come true, so it is necessary to propose a pressing and viable method;
3. Summarizing the principle of PMU placement in WAMS in according to the function of PMU, namely PMU placement method based on the main net framework observation. According to the concept of indirect observation, and based on the project practical view, and the MST and SA method, it deploys PMU on the main net framework and its key buses, and it also improved the state estimation with EMS measurement and PMU measurement. The information extending method and curve fitting method, which deals with date in the complementary system of PMU and EMS, are discussed. Then the proposed method is validated by case studies. The comparison results demonstrate that the proposed method is effective in theory;
4. In allusion to the “on-line beforehand decision-making, real time matching” and the third line of defence, it proposes the stability control flow based on PMU for interconnected power system, which is a real-time stability control. In this scheme, preventive control, emergency control and corrective control are designed to a closed-loop rolling control process,it will protect the stability of power system. Then it ameliorates the corrective control process, and presents a new control method which is based on PMU and EEAC method. This scheme can ensure the real-time quality and advance the veracity for the corrective control. The simulation shows that it has good prospects;
5. Proposing the concept of transmission section, key transmission section and so on, the meanings of transmission section are also discussed. After discussing the characteristic of Yunnan power grid’s transmission section, based on the simulation tool of FASTEST and BPA, the transient stability margin of Power Grid in 2006 and 2007 is analyzed and studied. In allusion to kV AC/DC Hybrid Power System of Yunnan power grid, it proposes the analyzing method for DC power flow based on PMU and transmission tie line group flow static state security restriction mode.
KEY WORDS: PMU placement; MST; SA; control tactic; transmission section.